1. Field of the Invention
The present invention relates to a color mixing inspection method, a color mixing inspection apparatus and a print apparatus in which a predetermined evaluation pattern is formed on a print medium such as paper and a film to inspect the presence of a color mixture by means of the evaluation pattern.
2. Description of the Related Art
Three types of methods as follows has been known as exemplary methods for ejecting ink from an ink jet print head (hereinafter simply referred to as a print head) mounted in an inkjet printing apparatus; more specifically, a method using an electromechanical converting body such as a piezo element, a method in which ink generates heat by irradiation of electromagnetic wave, such as a laser, so that the heat operates to eject the ink droplets, and a method in which ink is heated by an electrothermal conversion element having a heating resistor so that ink droplets are ejected by the action of film boiling.
Of these, a print head using an electrothermal conversion element is provided with an electrothermal conversion element in a printing liquid chamber, to which an electric pulse which is a printing signal is applied to generate heat so as to impart thermal energy to the ink. Then, a change in phase of a printing liquid occurred at that time brings the printing liquid to a boil to produce a foam pressure which is utilized to discharge the ink liquid from a tiny ejection port, thereby executing the print on a print medium. A color print head using an electrothermal conversion element generally has a group of ejection ports for ejecting ink droplets of each color, and ink channels for supplying ink to the group of ejection ports.
Furthermore, a print head includes a tank replacing type in which an ink tank and a print head are removable from each other, a head cartridge type in which a print head are integral with an ink tank container containing ink, and so on.
A method for manufacturing such as a print head includes a step of inspecting color mixing which evaluates the tone of the ink droplets ejected on the printing medium. This is for inspecting the presence of color mixing of ink generated due to a malfunction inside the print head. Conventionally, such a type of color mixing inspection has generally drawn a pattern for evaluation on the print medium so as to make a visual inspection by an inspector.
Furthermore, a method disclosed in Japanese Patent Laid-Open No. 10-151753 (1998) has been known as a method of detecting color mixing in an ink jet printing apparatus, for example. In accordance with this method, each basic color is printed on a print medium, and reading means reads the printed. Comparison means compares the read result with the acceptable range of tone of each basic color to determine whether or not the tone as a result of printing is normal.
However, the evaluation by an inspector varies depending on variations among individual inspectors who provide an evaluation, and also coming from not being able to conduct a quantitative evaluation. Also, the cost increases because it is a manual operation. Furthermore, the method for detecting mixing color in the ink jet printing apparatus described above may erroneously determine color which is not mixed color as being mixing color because the change in tone may be generated due to overlapping ink droplets ejected on a print medium, ejection failure, change in the amount of ejection, etc.